This application continues the investigation of short chain fatty acid-N-acetylmannosamine (SCFA-ManNAc) analogs represented by the lead compound Bu4ManNAc. This hybrid molecule derives HDACi growth inhibitory activity from its n-butyrate (Bu) groups and increases metabolic flux through the sialic acid biosynthetic pathway due to ManNAc generated after complete removal of n-butyrate by esterases. During the initial funding period of this project, it was discovered that partial hydrolysis products of Bu4ManNAc (e.g., 3,4,6-O-Bu3ManNAc) have a third mode of activity that suppresses the invasive potential of metastatic breast cancer cells at subcytotoxic doses. Because of the largely unmet and urgent clinical need for anti-metastatic therapeutics, the second funding period will investigate the mechanism underlying this newly found anti-cancer activity by focusing on the ability of the analogs to inhibit NF-kB (Aim 1) and alter glycosylation (Aim 2); in tandem, the current emphasis on cell-based assays will be transitioned into animal-level testing (Aim 3). In more detail, Specific Aim 1 will investigate the hypothesis that novel anti-cancer properties of a subset of SCFA-ManNAc analogs are a consequence of NF-kB inhibition through (at least in part) direct binding to pathway elements such as NFKB1; an auxiliary purpose of this investigation is to discover or design more highly and efficacious analogs for animal testing. In Specific Aim 2, mass spectrometry and bioinformatics strategies will be used to conduct a glycomics analysis of analog-treated cells; this work will provide a method for pharmacokinetic tracking of analog metabolism in vivo and will also shed mechanistic insights into the role of glycans in metastasis. Finally, Specific Aim 3 will transition this project into animal testing in rodents to determine oral availability, safety, pharmacokinetic properties and organ distribution, and efficacy in metastatic cancer models. Together, these experiments will substantially advance both the mechanistic and translational prospects for SCFA-ManNAc analogs, an emerging class of sugar-based cancer drug candidates.